1. Field of the Invention
The present invention relates to a cassette case for accommodating therein a tape cassette and an index sheet used therefor.
2. Description of the Prior Art
In general, a tape cassette employed for audio use and so on is accommodated and preserved in a plastic case when it is not in use. FIG. 1 generally shows an example of such conventional cassette case.
As shown in FIG. 1, a cassette case 21 is adapted to accommodate therein an audio compact cassette (hereinafter simply referred to as a tape cassette) 31 which is now widely available on the market. This cassette case 21 is composed of a casing 22 provided as a cassette case body and a lid 23, and the casing 22 and the lid 23 are pivoted by a hinge 24 so as to become freely openable and closable.
On the casing 22 side, engaging protrusions 25a, 25b are formed, which are inserted into reel shaft insertion apertures 32a, 32b of the tape cassette 31 for preventing reel hubs (not shown) in the tape cassette 31 from being rotated inadvertently, while a cassette supporting portion 26 is provided on the lid 23 side in order to support the tape cassette 31.
Conventionally, the cassette supporting portion 26 of the lid 23 is shaped as a bag (pocket-like shape) and is constructed such that, when the tape cassette 31 is inserted into the bag-shaped cassette supporting portion 26 from a front opening portion (i.e., a magnetic tape exposing portion into which a magnetic head, a pinch roller and so on are inserted) 33, the tape cassette 31 is supported therein so as to be rotated integrally with the lid 23, thus the tape cassette 31 being loaded onto and/or unloaded from the cassette casing 22 with ease.
In FIG. 1, reference numeral 27 designates an index sheet which is for use with this cassette case 21 and in which a musical program or the like is written. This index sheet 27 is inserted into the cassette case 21 under the condition such that it is sandwiched between the lid 23 and the tape cassette 31.
The thus constructed conventional cassette case encounters the following problems:
1. Since the cassette supporting portion 26 of the lid 23 is shaped as the bag and the tape cassette 31 is inserted into this bag-shaped cassette supporting portion 26 from its front opening portion 33 side to be supported therein, it is difficult to reduce the thickness of the cassette case 21. More specifically, since a trapezoid-shaped thick portion 34 is formed on the top and rear surfaces of the front opening portion 33 side of the tape cassette 31 so as to form the front opening portion 33, the cassette supporting portion 26 which receives this thick portion 34 requires a space (i.e., thickness) sufficient so that this thick portion 34 can be inserted thereto. As a consequence, the overall thickness of the cassette case 21 cannot be reduced.
2. Defective molds tend to occur in the molding-process of the lid 23. More specifically, when the lid 23 having the bag-shaped cassette supporting portion 26 is molded, because of the configuration of the bag-shaped cassette supporting portion 26, it is unavoidable that a metal mold apparatus whose cavity portion is formed by an upper mold 41, a lower mold 42 and a slide core 43 is employed as shown in FIG. 2. At the completion of the injection molding process, the upper mold 41 and the lower mold 42 are opened in the vertical direction and the slide core 43 are moved rearwardly in the lateral direction as shown by an arrow B, thereby to take out the molded product (lid). However, when the slide core 43 is moved rearwardly in the direction shown by the arrow B, a vacuum condition temporarily prevails in the bag-shaped cassette supporting portion 26 with the result that the molded product, which is not sufficiently cured, is deformed, which leads to the occurrence of defective molds.
Conventionally, Japanese Laid-Open Utility Model Gazette No. 60-163279 describes a cassette case which is intended to solve the problem 1 of the aforenoted problems. According to this previously-proposed cassette case, recess portions are respectively formed in the lid and the cassette casing so as to accommodate therein the thick portions of the tape cassette.
However, in this conventional cassette case, the cassette supporting portion of the lid is also shaped as the bag-like configuration which as a result cannot solve the above-described problem 2. Moreover, unavoidably, this cassette case is constructed such that the tape cassette is inserted into the cassette supporting portion of the lid from the direction opposite to the ordinary direction, that is, the tape cassette is inserted into the cassette supporting portion of the lid from its rear wall side (the side in which a mis-erase preventing tab is provided). In that event, the tape cassette is inserted into and/or taken out from the cassette case in the condition such that the front opening portion thereof is directed to the front side. There is then the large risk that the magnetic tape will be smudged by the fingers, incurring a serious problem in practical use.
Further, in such cassette case having the recess portions in which the thick portions of the tape cassette are accommodated, if the index sheet is inserted thereto, this index sheet hinders the thick portions of the tape cassette from being accommodated into the recess portions. Consequently, the index sheet should not be inserted into the cassette case or the index sheet must be formed small enough so as not to invade the recess portions of the cassette case, which considerably restricts the space of the index sheet in which the music program and so on are written.